Coauthored Publications with: Chastre


Acker, AV, Chastre C, Cholewicky A, Crisp B, Lúcio V, Elliott KS, Engström B, Gasperi A, Suikka A, Tsoukantas S, Vambersky J, Vantomme J.  2012.  fib Bulletin 63. Design of precast concrete structures against accidental actions. fib bulletin. :78., Number 63, Lausanne: Fédération internacionale du béton (fib) AbstractWebsite

Since the 1980’s, several buildings throughout the world have been subject to gas explosions, impact by cars or airplanes, or car bomb attacks. In many cases the effect of the impact or explosion has been the failure of a critical structural member at the perimeter of the building. After the failure, the load supported by that member could not be redistributed and part or all of the structure has collapsed in a progressive manner. The phenomenon that occurs when local failure is not confined to the area of initial distress, and spreads horizontally and/or vertically through the structure, is termed progressive collapse.

Progressive collapse is a relatively rare event, as it requires both an accidental action to cause local damage and a structure that lacks adequate continuity, ductility, and redundancy to prevent the spread of damage. It is technically very difficult and economically prohibitive to design buildings for absolute safety. However it is possible to construct precast concrete buildings that afford an acceptable degree of safety with regard to accidental actions.

A structure is normally designed to respond properly, without damage, under normal load conditions, but local and/or global damages cannot be avoided under the effect of an unexpected, but moderate degree of accidental overload. Properly designed and constructed structures usually possess reasonable probability not to collapse catastrophically under such loads, depending on different factors, for example: the type of loading; the degree and the location of accidental loading in regard to the structure and its structural members; the type of structural system, the construction technology, and the spans between structural vertical members, etc.

No structure can be expected to be totally resistant to actions arising from an unexpected and extreme cause, but it should not be damaged to an extent that is disproportionate to the original cause.

The aim of fib Bulletin 63 is to summarize the present knowledge on the subject and to provide guidance for the design of precast structures against progressive collapse. This is addressed in terms of (a) the classification of the actions, (b) their effect on the structural types, (c) the strategies to cope with such actions, (d) the design methods and (e) some typical detailing, all supplemented with illustrations from around the world, and some model calculations.

Tsoukantas, S, Toniolo G, Pampanin S, Ghosh SK, Sennour L, D’Arcy T, Sthaladipti S, Menegotto M, Özden Ş, Lúcio V, Chastre C, Dritsos S, Psycharis I, Topintzis T, Kremmyda G, Fernández-Ordóñez D, de Chefdebien A, Hughes S, Rajala L.  2016.  fib Bulletin 78. Precast-concrete buildings in seismic areas, 2016. fib bulletin. :273., Number fib Bulletin 78, Lausanne: International Federation for Structural Concrete (fib) Abstractfib_bulletin78.jpgWebsite

This document has a broad scope and is not focussed on design issues. Precast construction under seismic conditions is treated as a whole. The main principles of seismic design of different structural systems, their behavior and their construction techniques are presented through rules, construction steps and sequences, procedures, and details that should lead to precast structures built in seismic areas complying with the fundamental performance requirements of collapse prevention and life safety in major earthquakes and limited damage in more frequent earthquakes.The content of this document is largely limited to conventional precast construction and, although some information is provided on the well-known “PRESSS technology” (jointed ductile dry connections), this latter solution is not treated in detail in this document.The general overview, contained in this document, of alternative structural systems and connection solutions available to achieve desired performance levels, intends to provide engineers, architects, clients, and end-users (in general) with a better appreciation of the wide range of applications that modern precast concrete technology can have in various types of construction from industrial to commercial as well as residential. Lastly, the emphasis on practical aspects, from conceptual design to connection detailing, aims to help engineers to move away from the habit of blindly following prescriptive codes in their design, but instead go back to basic principles, in order to achieve a more robust understanding, and thus control, of the seismic behaviour of the structural system as a whole, as well as of its components and individual connections.

Acker, AV, Chastre C, Crisp B, Fernandez D, Lúcio V, Elliott KS, Hughes S, Jones G, Karutz H, Klein-Holte R, Maas S, Menegotto M, Tsoukantas S, van der Zee P.  2014.  fib Bulletin 74. Planning and design handbook on precast building structures, 2014. fib bulletin. :313., Number fib Bulletin 74, Lausanne: International Federation for Structural Concrete (fib) AbstractWebsite

In 1994 fib Commission 6: Prefabrication edited a successful Planning and Design Handbook that ran to approximately 45,000 copies and was published in Spanish and German.Nearly 20 years later Bulletin 74 brings that first publication up to date. It offers a synthesis of the latest structural design knowledge about precast building structures against the background of 21st century technological innovations in materials, production and construction. With it, we hope to help architects and engineers achieve a full understanding of precast concrete building structures, the possibilities they offer and their specific design philosophy. It was principally written for non-seismic structures.

The handbook contains eleven chapters, each dealing with a specific aspect of precast building structures.
The first chapter of the handbook highlights best practice opportunities that will enable architects, design engineers and contractors to work together towards finding efficient solutions, which is something unique to precast concrete buildings.
The second chapter offers basic design recommendations that take into account the possibilities, restrictions and advantages of precast concrete, along with its detailing, manufacture, transport, erection and serviceability stages.
Chapter three describes the precast solutions for the most common types of buildings such as offices, sports stadiums, residential buildings, hotels, industrial warehouses and car parks. Different application possibilities are explored to teach us which types of precast units are commonly used in all those situations.
Chapter four covers the basic design principles and systems related to stability. Precast concrete structures should be designed according to a specific stability concept, unlike cast in-situ structures.
Chapter five discusses structural connections.
Chapters six to nine address the four most commonly used systems or subsystems of precast concrete in buildings, namely, portal and skeletal structures, wall-frame structures, floor and roof structures and architectural concrete facades.
In chapter ten the design and detailing of a number of specific construction details in precast elements are discussed, for example, supports, corbels, openings and cutouts in the units, special features related to the detailing of the reinforcement, and so forth.
Chapter eleven gives guidelines for the fire design of precast concrete structures. The handbook concludes with a list of references to good literature on precast concrete construction.

Hughes, S, Acker AV, Chastre C, Gasperi A, Jones G, Karutz H, Krohn J, Laliberté D, Lindstrom G, Ronchetti A, Sennour L, Seshappa V, Sthaladipti S, Suika A, Tillman M, Tsoukantas S.  2017.  fib Bulletin 84. Precast Insulated Sandwich Panels. fib Bulletin 84. , Number fib Bulletin, Lausanne: International Federation for Structural Concrete (fib) Abstract

Precast concrete sandwich panels started being used as cladding for buildings, together with the rise of industrial prefabrication, during the mid-20th century. Since then, society and industry have become increasingly aware of energy efficiency in all fields, for both affordability and sustainability consciousness. As such, buildings have been subject to increasingly stringent requirements with the technology of sandwich panels kept continually at the forefront.
Nowadays, sandwich panels have reached the highest standards of functional performance as structural efficiency, flexibility in use, the speed as well as of aesthetic appeal. These combine in building construction with the well-known advantages of prefabrication; such as construction, quality consciousness, durability and sustainability. Sandwich panels have gained more and more important in their field, thus representing quite a significant application within the industry of prefabrication and an important share of the market.
The Commission ‘Prefabrication’ is keen to promote the development of all precast structural concrete products and to transfer the knowledge to practical design and construction. Now filling a strategic gap, by issuing this Guide to Good Practice, which includes design considerations, structural analysis, building physics, use of materials, manufacturing methods, equipment, field performance, and provides a comprehensive overview of the information currently available worldwide. The Commission is particularly proud that this document is a result of close cooperation with PCI and that it will be published by both fib and PCI. This cooperation started six years ago, first with comparing the different approaches to several issues, then progressively integrating up to producing common documents, like this one, that wasn’t yet treated in a specific Guide by either body.

Biscaia, HC, Chastre C.  2018.  Theoretical analysis of fracture in double overlap bonded joints with frp composites and thin steel plates, 2018/03/01/. Engineering Fracture Mechanics. 190:435-460. AbstractWebsite

The effective stress transfer between the fiber reinforced polymers (FRP) and the steel substrate is crucial for the successful retrofit of existing steel structures with FRP composites. However, there are no standard tests for FRP-to-steel interfaces, wherefore different test configurations have been used in recent years to assess the bond behaviour in these interfaces. The present study shows that the choice of test configuration is highly important and leads to different transfer stresses between the FRP and steel composites and consequently, has a direct influence on the strength of the bonded joint. Therefore, it is important to understand the debonding process that occurs in each test and avoid misinterpretations, erroneous analyses and dangerous characterizations of the interfacial behaviour of these interfaces. The current study presents a new analytical approach for the prediction of the debonding of FRP-to-steel interfaces when double-lap pull or double-strap tests are used.

Chastre, C, Lúcio V, Acker AV, Crisp B, Gutstein D, Saraiva F, Doniak Í, Krohn J, Viegas JB, Ferreira M, Menegotto M, el Debs M, Hughes S, Tsoukantas S, Pampanin S.  2012.  Estruturas Pré-Moldadas no Mundo. Aplicações e Comportamento Estrutural, 2012. :320., Brasil: Fundação da Faculdade de Ciência e Tecnologias da Universidade NOVA de Lisboa AbstractWebsite

A indústria do betão pré fabricado é, por tradição, inovadora, precursora de novas tecnologias e de novos materiais.O processo produtivo de estruturas com elementos pré-fabricados difere significativamente do das estruturas betonadas em obra pelo facto de uma parte, ou a totalidade, dos elementos da estrutura serem produzidos em fábrica, em condições de produção melhoradas em relação às condições da obra, e serem posteriormente transportados para a obra, onde são, finalmente ligados entre si. A produção em fábrica é efectuada em ambiente protegido do Sol e da chuva, com operários fixos e com formação profissional para desenvolverem tarefas com procedimentos normalizados. Consequentemente, os elementos executados em fábrica possuem melhor qualidade, sob vários aspectos, do que as estruturas executadas em obra.Este livro divide-se em duas grandes áreas, numa primeira abordam-se algumas aplicações de estruturas pré-moldadas no mundo e numa segunda parte descreve-se o seu comportamento estrutural face a diferentes acções. Nos primeiros capítulos relata-se a experiência da pré-fabricação em três países de diferentes continentes: o Brasil, Portugal e a Austrália e revelam-se novas oportunidades que poderão surgir para a indústria da pré-fabricação. Nos capítulos seguintes dá-se um especial enfoque à investigação do comportamento das ligações (rígidas e semi-rígidas). Aborda-se o projecto de estruturas de betão pré-fabricado às acções acidentais. E por fim, dedicam-se os últimos capítulos ao comportamento das estruturas pré-fabricadas face às acções sísmicas. Nesta área, o bom desempenho das estruturas e grande parte do conhecimento e da tecnologia actual advém da resposta dada pelos engenheiros, investigadores e construtores aos fenómenos naturais que afectam as nossas construções, como comprova o desempenho das ligações dúcteis resistentes a momentos em edifícios pré fabricados de betão no verdadeiro teste sísmico que foram os sismos de Christchurch de 2010 e 2011.

Book Chapter

Chastre, C, Lúcio V, Tsoukantas S.  2012.  Princípios básicos para a conceção de estruturas de edifícios em zonas sísmicas. Estruturas Pré-moldadas no Mundo - Aplicações e Comportamento Estrutural. :227-248.: Fundação da Faculdade de Ciências e Tecnologia da Universidade NOVA de Lisboa Abstract
Chastre, C.  2017.  Prólogo. Cáceres-Florencia, patrimonio vivo: Ensayos técnico-arquitectónicos. 3:11-15., Cáceres: Grupo de Investigación de Construcciones Arquitectónicas de la Universidad de Extremadura Abstract

Este livro apresenta diferentes perspetivas sobre o património arquitetónico em Espanha e Itália, debruçando-se sobre temas que estão na ordem do dia, como a reabilitação do património arquitetónico ou as acessibilidades ao mesmo, sejam elas na forma física ou digital, sendo os autores profundos conhecedores desta área. Nas intervenções a realizar no património edificado é fundamental ter um conhecimento aprofundado do projeto, da história e do processo construtivo da obra, bem como do seu comportamento estrutural. De acordo com o ICOMOS estas intervenções devem ser realizadas utilizando as técnicas mais adequadas, baseadas num diagnóstico apropriado e na compreensão dos materiais existentes. De igual forma, os estudos no edificado monumental devem ser realizados com o menor grau de intrusão e o máximo respeito pela sua integridade física, seguindo os princípios de salvaguarda do património arquitetónico definidos na carta internacional de Atenas.O livro divide‐se em duas grandes áreas: numa, abordam‐se os assuntos que se enquadram essencialmente no âmbito da conservação e reabilitação do património arquitetónico e na outra são apresentados os temas mais dedicados à acessibilidade do público ao património arquitetónico e à sua divulgação online. Os trabalhos apresentados no âmbito da conservação e reabilitação do património arquitetónico seguem na essência as recomendações do ICOMOS em relação à necessidade de compreensão da construção existente, ao desenvolvimento de novas técnicas e dos materiais mais adequados aos trabalhos de conservação e reabilitação, assim como na realização de testes em modelos experimentais à escala, tendo por objetivo avaliar o comportamento da estrutura antes e após a reabilitação. O património arquitetónico construído constitui uma parte importante da história da civilização humana e é um fator determinante da nossa identidade coletiva que importa preservar para as gerações futuras. Com a sua intervenção na conservação, reabilitação, valorização e divulgação do património construído, os autores deste livro estão a cumprir um importante papel na nossa sociedade, preservando um legado que nos foi deixado pelos nossos antepassados.

Chastre, C.  2019.  Preface. 2nd International Conference on Building Materials and Materials Engineering - ICBMM 2018. 278, Lisbon, Portugal: MATEC Web of Conferences. Abstract

The 2nd International Conference on Building Materials and Materials Engineering (ICBMM 2018) was held at the University of Lisbon, Portugal, from 26 to 28 September, 2018. The objective of the Lisbon conference was to provide a platform for researchers, engineers, academics, as well as industrial professionals from all over the world, to present their research results and development activities in Building Materials and Materials Engineering.ICBMM 2018 was an opportunity for researchers, engineers and academics to further develop Building Materials and Materials Engineering. Attendees benefitted a lot from expert practitioners and researchers who presented the latest trends in theoretical and practical domains of Building Materials and Materials Engineering. Distinguished professors also delivered their keynote speeches on the latest developments in their respective fields. Among the keynote and plenary speakers were Prof. Carlos Chastre from NOVA University of Lisbon, Portugal; Prof. Paulo Mendonça from University of Minho, Portugal; Dr. Mascarenhas Mateus from University of Lisbon, Portugal; Prof. Rudolf Hela from Brno University of Technology, Czech Republic.The current set of conference proceedings present a selection of papers submitted by researchers from a variety of universities, research institutes and industries. All papers were peer-reviewed by conference committee members and a panel of international reviewers who selected the papers to be published based on their quality and relevance to the topic of the conference. This volume presents recent advances in the field of Materials Science and Engineering, Materials Properties, Measuring Methods and Applications, Materials Manufacturing and Processing, Civil and Structural Engineering, Architecture and Urban Planning.We would like to thank all the authors who have contributed to this volume and also the organizing committee, reviewers, speakers, co-chair persons, sponsors and all the conference participantsfor their strong support to ICBMM 2018, making this conference such a great success. We look forward to meeting you in ICBMM 2019!

Chastre, C, Lúcio V.  2012.  Estruturas pré-moldadas no mundo. Estruturas Pré-moldadas no Mundo - Aplicações e Comportamento Estrutural. :1-6.: Fundação da Faculdade de Ciências e Tecnologia da Universidade NOVA de Lisboa Abstract
Ludovico-Marques, M, Chastre C.  2018.  Consolidation works on sandstone monuments: A new approach. Handbook of Materials Failure Analysis: With Case Studies from the Construction Industries. (Abdel Salam Hamdy Makhlouf, Mahmood Aliofkhazraei, Eds.).:235-254.: Butterworth-Heinemann Abstract

Abstract Sandstones are widely used in the building elements of the world’s stone monuments. Alveolization due to salt crystallization-dissolution is the most important degradation pattern found on the Middle Ages’ sandstone façades of St. Leonardo’s Church in Portugal. An outstanding case of widespread distribution of deep and large alveolization patterns found mainly on portals and vaults of its sandstone façades appeared as a result of the past and present proximity of the seashore. On stonewall façades, a new approach of consolidating products’ treatments using the total head was followed in order to allow full absorption of stone. Physical and mechanical tests were carried out on selected representative specimens of varieties of sandstones on the monument. Treatments with ethyl silicates were assessed by means of its effectiveness, harmfulness, and durability. The comparison of results between the application of this new procedure on this stone monument and the traditional intervention treatments highlighted the potential viability of the former to overcome difficult conditions of absorption of consolidating products.

Chastre, C, Lúcio V.  2012.  Torres pré-fabricadas de betão para suporte de turbinas eólicas. Estruturas Pré-moldadas no Mundo - Aplicações e Comportamento Estrutural. :91-106.: Fundação da Faculdade de Ciências e Tecnologia da Universidade NOVA de Lisboa Abstract
Chastre, C, Ludovico-Marques M.  2018.  Nondestructive testing methodology to assess the conservation of historic stone buildings and monuments. Handbook of Materials Failure Analysis: With Case Studies from the Construction Industries. (Abdel Salam Hamdy Makhlouf, Mahmood Aliofkhazraei, Eds.).:255-294.: Butterworth-Heinemann Abstract

Earthquakes, soil settlements, traffic vibrations, and air pollution are some of the actions that can affect historic old buildings. Besides these, the lack of continuous maintenance puts a large part of this heritage in risk due to structural problems that reduce their own safety and that of their users. The preservation and risk mitigation of built cultural heritage require the use of reliable tools in order to assess its state of conservation and to identify and prevent potential vulnerabilities. Having this in mind, it is not possible to carry out destructive tests in most historic old buildings, so it is preferable to opt for nondestructive tests (NDT) or alternative methodologies that allow the physical and mechanical characterization of materials and structure. In this chapter, a general view of NDT methods used in historic buildings to obtain the geometrical information, the damage mapping, the mechanical and physical characterization, and the petrographic analysis of stones is presented. An alternative methodology to physically and mechanically characterize the stone of historic buildings using NDT tests is also proposed. The chapter ends with a case study carried out in the St. Leonard’s Church, a Portuguese monument built in Atouguia da Baleia village in the 13th century, where the alternative methodology here presented was applied. The final results of this study show that the methodology proposed allows the obtention of stress-strain curves in a completely nondestructive way, based on the water absorption coefficient at low pressure.

Lúcio, V, Chastre C.  2012.  Ligações rígidas em estruturas pré-fabricadas. Estruturas Pré-moldadas no Mundo - Aplicações e Comportamento Estrutural. :137-166.: Fundação da Faculdade de Ciências e Tecnologia da Universidade NOVA de Lisboa Abstract
Pacheco, J, de Brito J, Chastre C, Evangelista L.  2017.  Reliability analysis: the next step towards recycled aggregates concrete affirmation. Construction projects: improvement strategies, quality management and potential challenges. (Kimberly Hall, Ed.).:1-54.: Nova Science Publishers: New York, United States of America Abstract

TThis chapter concerns the need to evaluate the reliability of structural elements produced with recycled aggregates concrete (RAC) in order to address some designers’ scepticism towards the use of this eco-friendly material. The current knowledge on RAC’s behaviour demonstrates its viability for structural purposes. However, of the investigations performed so far very few are related to a fundamental aspect towards RAC world-wide application as a structural material: structural codes have a probabilistic basis.After briefly presenting the state-of-the-art knowledge on the material properties and structural behaviour of RAC, the limitations of the current knowledge are debated. Afterwards, an introduction to structural codification is presented, as well as the fundamentals of reliability analysis. Examples of code verifications are contextualized with their underlying assumptions and the information necessary for code calibration is discussed. The role of reliability in the calibration of structural codes is shown, common techniques for reliability calculations are briefly explained, and relevant references in the area are cited for the readers’ perusal.Having established how structural codes are calibrated, the state-of-the-art on the probabilistic and statistical knowledge of RAC properties is reviewed. The implications of the very reduced number of studies on this area are discussed and the need to conduct further studies is emphasized.Afterwards, investigations that used reliability analysis to calibrate partial safety factors applicable to RAC are reviewed. The methodology of each investigation is presented, the experimental tests that led to the definition of the probabilistic information of the RAC’s parameters are described and the need to have a wide range of data coming from different RAC compositions and aggregate sources is debated.This chapter finishes by contextualizing the current knowledge on RAC properties with the necessary information for code calibration procedures. The relevance of a code proposal towards RAC affirmation as a structural material is highlighted, as well as the requirements of such code. Suggestions for future studies are made.

Ludovico-Marques, M, Chastre C.  2016.  Effect of Artificial Accelerated Salt Weathering on Physical and Mechanical Behavior of Sandstone Samples from Surface Reservoirs. Handbook of Materials Failure Analysis With Case Studies from the Oil and Gas Industry. (Abdel Salam Hamdy Makhlouf, Mahmood Aliofkhazraei, Eds.).:215-233.: Butterworth Heinemann - Elsevier Abstract


Conference Paper

Chastre, C, Monteiro A, Biscaia H, Franco N.  2016.  Novo sistema de reforço estrutural de vigas de betão armado com compósitos de FRP ancorados internamente por aderência, 27-29 September. II Encontro Luso-Brasileiro de Degradação de Estruturas de Betão. :12p.., LNEC, Lisbon, Portugal Abstractdegrada_2016_-_carlos_chastre_-_ext-abstract.pdf

A reabilitação de estruturas de betão armado com compósitos de FRP tem tido uma grande aceitação em especial devido às excelentes características de durabilidade dos materiais compósitos, ao seu baixo peso e às suas elevadas prestações mecânicas. Contudo, o comportamento elástico-linear dos compósitos de FRP e a sua forma de aplicação pode originar roturas prematuras, quer na técnica de reforço EBR (Externally Bonded Reinforcement), em que o compósito é colado externamente, quer na técnica NSM (Near Surface Mounted) em que o compósito é inserido na zona do recobrimento. No sentido de minimizar o risco de roturas prematuras e ao mesmo tempo aumentar a ductilidade dos elementos reforçados, desenvolveu-se um novo sistema de reforço estrutural em que as armaduras são ancoradas internamente por aderência. A fim de validar o novo sistema de reforço estrutural com compósitos de FRP foi realizado um programa experimental que incluiu o ensaio de vigas de betão armado (BA) reforçadas com as seguintes técnicas de reforço: EBR, NSM e pela nova técnica CREatE (continuous reinforcement embedded at ends). Neste artigo descrevem-se os ensaios experimentais realizados e analisam-se os resultados obtidos. As vigas de BA ensaiadas tinham seção em T, com um vão de 3,0 m e uma altura de 0,3 m e foram solicitadas em flexão em 4 pontos e testadas até a rotura. A técnica CREatE provou ser a mais eficaz das três alternativas testadas mobilizando a totalidade do CFRP e apresentando a maior capacidade resistente e a ductilidade mais elevada.

Pacheco, J, de Brito J, Chastre C, Evangelista L.  2019.  Reliability of the bond strength of recycled coarse aggregate concrete, May, 27-29, 2019. Proceedings of the fib Symposium 2019: Concrete - Innovations in Materials, Design and Structures. :913-920., Kraków, Poland Abstract

An analysis on the effect of the incorporation of coarse recycled concrete aggregates on the bond strength between concrete and embedded steel reinforcement is presented. The model’s uncertainty of the Level I provision of the anchorage length of fib Bulletin 72 on ribbed steel/recycled aggregate concrete bond is quantified. Afterwards, reliability analyses on the bond strength are made and a partial safety factor for the anchorage length of recycled concrete elements is proposed. The model’s uncertainty is evaluated through data from pullout tests, the only type of bond test that has been so far performed extensively on recycled aggregate concrete specimens. The limitations of this test in reproducing the bond of actual structural elements is discussed, and the model’s uncertainty is converted to that of lap splice tests. The bond strength of recycled aggregate concrete design was found to be less reliable than that of natural aggregate concrete, especially in the absence of confining reinforcement. For concrete with full recycled aggregate incorporation, a 25% increase in the anchorage length is proposed. Additional testing on the bond strength of lapped splices or beam-end specimens is recommended.

Ludovico-Marques, M, Chastre C.  2014.  Conservation of sandstone monuments: a new approach in consolidation treatments, 16-19 December. 40th IAHS Word Congress of Housing. Sustainable Housing Construction.. :ID211(10p)., Funchal, Portugal Abstract40_iahs_ludovico-marques_-_ext.abstract.pdf

Sandstones are very important in the building elements of world’s historical and cultural heritage. The façades of St. Leonard’s church in Atouguia da Baleia village in western region of Portugal are an outstanding example of the effect of alveolization on going for several centuries. In Middle ages there was an harbour and a sodium chloride rich environment near this church was responsible for this significant stone degradation pattern.
A new approach of consolidating products application on stone walls façades based on Karsten pipe using total head to allow full absorption of stone was followed.
Experimental research, based on physical and mechanical tests, was carried out on selected representative samples of a variety of sandstones on monuments treated with ethyl silicates in order to assess the effectiveness and harmfulness of these treatments.
The comparison of results between traditional immersion applications and Karsten pipe’s based procedure on stone monument indicate the potential viability of this new approach when difficult conditions of consolidating products’ absorption occurs on stone monuments.

Biscaia, H, Chastre C, Cruz D, Franco N, Nunes R.  2016.  Reforço à flexão de pavimentos antigos de madeira com recurso a laminados de fibras de carbono, 4-6 July 2016. TEST&E 2016 - 1º Congresso de Ensaios e Experimentação em Engenharia Civil. :8., IST, Lisbon, Portugal Abstractteste2016_-_01049_-_biscaia.pdf

O dimensionamento de vigas de madeira aos Estados Limites de Utilização (ELUt) tem limites muito apertados tanto para ações de curto prazo como para ações de longo prazo. Uma solução eficiente para este problema passa por aumentar as seções transversais das vigas. Porém, este tipo de solução não só acarreta um aumento de custos como também altera profundamente arquitetura original do edifício abrindo, por conseguinte, uma oportunidade para encontrar outras soluções mais eficientes. Neste sentido, o uso de armaduras de reforço em vigas de madeira pode ser considerado como uma solução promissora uma vez que as estruturas, novas ou velhas, manteriam o aspeto estético original sem introduzir nos elementos reforçados, um aumento significativo do seu peso próprio, melhorando o seu desempenho face a ações de curto e longo prazo. O presente estudo é dedicado à análise de vigas de madeira antigas reforçadas à flexão com materiais compósitos de fibras de carbono, vulgarmente designados na literatura internacional por Carbon Fiber Reinforced Polymers (CFRP). Neste trabalho, foram reforçados e ensaiados à flexão pavimentos antigos de madeira tendo-se analisado os respetivos desempenhos aquando da utilização de uma técnica de reforço por colagem tradicional (Externally Bonded Reinforcement - EBR) e aquando da utilização de uma técnica de reforço por colagem inovadora (Continous Reinforcement Embedded at Ends - CREatE). Os ensaios experimentais permitiram verificar que a técnica de colagem inovadora CREatE confere aos pavimentos de madeira uma maior rigidez e resistência face à técnica tradicional conseguindo se mobilizar a totalidade do compósito de CFRP.

Pacheco, J, de Brito J, Chastre C, Evangelista L.  2017.  Model uncertainty of recycled aggregate concrete beams subjected to bending, 21-22-23 June 20. HISER International Conference on Advances in Recycling and Management of Construction and Demolition Waste. , Delft, The Netherlands Abstract

This paper investigates whether the model uncertainty of reinforced recycled aggregate concrete (RAC) beams subjected to bending differs from that of reinforced natural aggregate concrete (NAC) beams. An introductory remark concerning the importance of the codification of RAC structural design is made and notions concerning model uncertainties and their role on structural codification are given. Afterwards, the criteria used in the construction of a database of RAC and NAC beams are referred before presenting the key findings of an analysis on the model uncertainty of the cracking, yielding and ultimate moments of beams subjected to four-point bending tests. The analytical moments were calculated following Eurocode 2 provisions. Probabilistic models for model uncertainties are proposed. Negligible differences in the model uncertainty of NAC and RAC beams are reported.

Chastre, C, Ludovico-Marques M, Saumell J, Guerrero M, Delgado M.  2014.  Surveying of Sandstone Monuments: New and Traditional Methodologies to Assess Viability of Conservation Actions, 16-19 December 2. 40th IAHS Word Congress of Housing. Sustainable Housing Construction.. :ID307(10p)., Funchal, Portugal Abstract40_iahs_chastre_-_ext.abstract.pdf

Sandstone building stones are important in the building elements of Portuguese monuments, particularly in the western and southern regions. Alveolization due to salt crystallization was the most important degradation pattern found in the old sandstone façades of St. Leonardo’s Church, a Portuguese monument built in Atouguia da Baleia village in the Middle Age. Its sandstone façades have a widespread distribution of deep and large alveolization patterns mainly on portals and vaults that appeared as a result of the past and present vicinity of seashore. In this paper a summary of conservation interventions carried out in the past century in St. Leonardo’s Church is presented, as well as a summary of the studies carried out in the last decade. Then the degradation patterns on the sandstone walls of St. Leonard’s Church are shown and finally the evolution of the alveolization occurred on the sandstone walls over the last sixty to seventy years is analysed. Visual inspection of sandstone walls is compared with a survey performed by laser scanning, which seems to be a powerful technology to carry out 3D geometric modelling of the building elements of stone monuments and also the 3D mapping of stone degradation patterns.

Chastre, C, Biscaia H, Monteiro A, Franco N.  2016.  Análise experimental de vigas de betão armado reforçadas à flexão com compósitos de FRP, 4-6 July 2016. TEST&E 2016 - 1º Congresso de Ensaios e Experimentação em Engenharia Civil. :8., IST, Lisbon, Portugal Abstractteste2016_-_01066_-_chastre.pdf

O reforço das estruturas de betão armado com compósitos de FRP tem tido um incremento considerável nos últimos anos devido às características de durabilidade e das elevadas relações resistência-peso e rigidez-peso dos compósitos de FRP comparativamente com outros materiais de reforço. A fim de analisar o comportamento de diferentes soluções de reforço estrutural de vigas de betão armado (BA) com compósitos de FRP foi realizado um programa experimental que incluiu o ensaio de vigas de BA reforçadas com as seguintes técnicas de reforço: EBR (Externally-Bonded Reinforcement), NSM (Near Surface Mounted) e pela técnica CREatE (continuous reinforcement embedded at ends). As vigas de BA ensaiadas tinham seção em T, com um vão de 3,0 m e uma altura de 0,3 m e foram solicitadas em flexão em 4 pontos e testadas até a rotura. A técnica CREatE provou ser a mais eficaz das três alternativas testadas mobilizando a totalidade do CFRP e apresentando a maior capacidade resistente e a ductilidade mais elevada.

Pacheco, J, de Brito J, Chastre C, Evangelista L.  2018.  Avaliação dos resultados de resistência à compressão de betão pronto produzido em centrais portuguesas, 7 a 9 de novembr. Encontro Nacional Betão Estrutural - BE2018. :10., LNEC, Lisboa, Portugal Abstract

Este artigo avalia se, para especificações de betão correntes, a resistência à compressão de betão pronto é significativamente dependente da central que o produziu, bem como se a variabilidade entre amassaduras de uma determinada composição é dependente da classe de resistência especificada. É apresentado um parâmetro probabilístico que converte a resistência à compressão característica especificada para a resistência à compressão expectável em provetes de betão cúbicos em condições padronizadas.É feita uma análise estatística e probabilística dos resultados de ensaios de resistência à compressão aos 28 dias de betão pronto produzido em três centrais de betão portuguesas durante o ano de 2017. Após a avaliação da representatividade da base de dados analisada, é feito um estudo comparativo dos parâmetros estatísticos dos dados de produção das diferentes centrais e é avaliada a influência da classe de resistência à compressão do betão nestes parâmetros. Define-se e analisa-se um parâmetro probabilístico que converte a resistência à compressão especificada para a resistência potencial de betão, para cubos de 150 mm. Este parâmetro contribui para uma futura proposta de um modelo probabilístico, a ser utilizado em análises de fiabilidade, que converte a resistência à compressão especificada para a resistência à compressão de elementos de betão em obra.Quer a análise estatística dos ensaios de resistência à compressão, quer o parâmetro de conversão são comparados com os resultados de investigações internacionais na área, aferindo-se se a qualidade da produção de betão pronto nacional é semelhante à de outras regiões.

Chastre, C.  2014.  Materiais e tecnologias de reforço de estruturas de betão - potencialidade e limitações, 2014. REHABEND 2014 - Congresso Latinoamericano "Patología de la construcción, Tecnología de la rehabilitacíon y gestión del patrimonio".. , Santander Abstractcarlos_chastre__-_rehabend2014_-_santander.pdf

O desenvolvimento da engenharia de estruturas tem tido grandes avanços nas últimas décadas, baseados em novos meios de cálculo e na investigação em novos materiais e tecnologias a eles associadas. Por sua vez, as atividades de reparação e reforço têm vindo a incrementar devido ao envelhecimento e à degradação das estruturas de betão, o que consequentemente tem dado origem ao aparecimento de novos materiais e tecnologias de reparação e reforço de estruturas. A utilização destes novos materiais na construção tem vindo a substituir outros materiais e técnicas existentes, requerendo, no entanto, mais estudos sobre o seu real comportamento quer em termos de caracteristicas mecânicas quer em termos de durabilidade.